[PATCH v3 1/2] mtd: spi-nor: issi: is25wp256: Init flash based on SFDP

[Michael Walle]

Hi,

Am 2022-12-21 01:30, schrieb Guenter Roeck:
> With this patch in place, qemu emulations with is25wp256 fail to
> instantiate the flash. Specifically, this affects the qemu sifive_u
> emulation. The resulting error message is:
> 
> spi-nor spi0.0: BFPT parsing failed. Please consider using
> SPI_NOR_SKIP_SFDP when declaring the flash
> spi-nor: probe of spi0.0 failed with error -22

qemu is to blame here. It doesn't fully emulate the flash. Esp. not
the SFDP tables. See also [1]. Adding the .sfdp_read hook with the
corresponding binary [2] should fix your issue.

[1] 
https://lore.kernel.org/qemu-devel/7827c791b7f91f4eb216b33473dd6103@walle.cc/
[2] 
https://lore.kernel.org/linux-mtd/CAHyZL-ch=mr0x_19e6P9G+Z4sW2iJXW9nTnXUNAhn+pTptN2ww@mail.gmail.com/

-michael